If nothing else, a sacrificial board that absorbs the kicks, mops, bumps, splashes, kids toys, and whatever else smacks into them without jeopardizing the cabinet.

Also allows for shimming and leveling under each individual cabinet and then being able to cover it with a toe kick board to tie it all together and cover it up.

Toe kick board can be scribed to compensate for any discrepancies in the flooring.

Doubles as baseboard in the area butting the cabinets.

Women with high heels that have that extra dead space in front of their toes within the shoe so that they can get closer to the cupboard.

A good place to trap debris that floats around on your floor in-between cleanings.

Usually an open area just under the cabinet above the toe kick that allows for ventilation of the underside of the cabinet so it doesn't trap air / humidity.

Allows for area under the cabinet to run water lines for refrigerator water lines, diswasher, R/O system, and or electric.

Allows for area under the cabinet to run a heat vent.